<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>标题标签</title>
</head>
<body>
  <!-- h1标签在一个网页中只能用一次, 用来放新闻标题或网页的logo -->
  <!-- h2 ~ h6没有使用次数的限制 -->
  <h1>一级标签</h1>
  <h2>二级标签</h2>
  <h3>三级标签</h3>
  <h4>四级标签</h4>
  <h5>五级标签</h5>
  <h6>六级标签</h6>
</body>
</html>